The silverback gorilla named Kwashi was born at the Memphis Zoo in 1982 and arrived at the Cincinnati Zoo in May of 2010.

Zoo officials say they first noticed a change in Kwashi's eating habits on Sunday. By early Monday, the 320-pound gorilla was lethargic, unable to stand on his own and dehydrated. He died a short time later.

Officials say a necropsy performed Tuesday determined Kwashi died from a serious abdominal infection.

Officials have collected tissue samples and sent them to a pathologist. They say this information will allow zoos to continue to learn about the species.